Means for drying air.



L. BLOCK. 7 MEANS FOR DRYING AIR.

APPLICATION FILED SEPT.20, 1909.

961,710. Patented June 14,1910.

- WITNESSES: ma Mm? QM inn WM 8% EINI A ATNT LOUIS BLOCK, OF MAMARONECK,NEW YORK.

MEANS FOR DRYING AIR.

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Specification of Letters Patent.

Patented June 14, 1910..

Application filed September 20, 1909. Serial No. 518,679.

plied to the treatment of air for use in blast furnaces for thereduction of ore to the condition of metallic iron. I can employ thecommonly known blast furnace, preferably the modern examples working ona large scale.

The quantity of water wastefully carried by the air into the furnace hasbefore been successfully reduced by lowering the temperature of the airand causing it to deposit its moisture. I adopt that plan and havediscovered improved means for effecting and regulating such action, andhave devised a special construction of a tower and associated parts, andan ice-pit or refrigerating-pit and connected mechanism constituting anapparatus for attaining this continuously and with a high degree ofperfcction.

I attach importance to the merely fuelsaving result of reducing thequantity of water in the air blown into the furnace, but there is farmore importance in the qualitative effect of uniformity. When the air iis uniform, and can be depended on as varying in nothing, the furnacemen with their usual careful attention to choosing and weighing therapidly recurring additions of ores and fluxes can make all thesuccessive tappings practically uniform for indefinite periods. Iarrange that ice in the dense transparent form, ordinarily so-called,more efficient for a given bulk than the 'spicu'lar form,*frost,shall bepresented uniformly to a liberal supply of water which is used over andover, and that the ice shall increase when the cooling is below themean, and decrease when it is above the mean. I so present such water tothe incoming air as to certainly and efi'cctually cool the air to apractically uniform temperature. My appa ratus is intended to cool theair with certainty to near 32 Fah., and as the quantity of water thuscirculating becomes excessive by the precipitation as the temperature ofthe air is lowered, my apparatus discharges all surplus while it is inits warmest condition. The invention thus not only serves as anautomatic means of avoiding all small and rapidly recurring fluctuationsin the temperature in a manner somewhat analogous to the function of afiy-wheel in regulating machinery, but also leads away the stream ofsurplus water without allowing it to descend into the refrigerating-pitand Waste the ice there.

The following is what I consider a good means of carrying out theinvention.

The accompanying drawings form a partof this specification.

Figure 1 is a central vertical section. Fig. 2 is a vertical section ofa portion at right angles thereto, on the line 22 in Fig. 1, and Fig. 3is a general side elevation in outline showing the same parts with thead dition of the ordinary blowing engine, stove and blast furnace towhich the air having its moisture reduced to a uniformly small amount issupplied.

Similar letters of reference indicate corresponding parts in all thefigures where they occur.

A is a non-conducting casing or tower through which the air is passed.Its function is to inclose and support the parts which bring the airdown to an "ice-cold temperature by compelling the air and the water tomove in extended contact,the air moving upward and the water downward.

At a convenient level which I will designate as the first story the airis received radially in all directions at any temperature and with anydegree of saturation with moisture which it may chance to possess as itcomes from the external atmosphere. The large volume of air required fora blast furnacc flows upward subjected to strongly cooling influences,and emerges at the top with its temperature reduced to a low degree, (Iwill assume it to be 33 Fah.).

I will designate as the first story and mark a the chamber or space intowhich the air first enters. I will designate as the refrigerating orice-pit and. mark (I/* the considerable space below. In this importantportion are distributed tiers of pipe marked B sup- ,plied withexpanding ammonia, through a pipe B and the ammonia expanded into thegaseous form and developing the required cold by its expansion flows outfrom the upper part of the ice pit through pipe B oration of the ammoniais applied to the air indirectly. The strong cooling effect produced bythe pipes B is developed in lowering the temperature of a sufliclentlyliberal quantity of water C, which I circulate by pumping up anddistributing evenly and allowing to flow "down.

The water in its descent through the tower is spread in a thin rapidlydescending coating, on boards, absorbing the heat of the air which isflowing upward past it. The Water is first received in a trough E at ahi h level,

having lateral spouts E. These dehver into over-flow troughs G,which-interrupt and detain the water and allow it to be slowlydischarged with uniformity, descending in rapidly succeeding drops orsmall streams upon a series of cypress boardsJ, placed parallel on edge.These boards are thus wet andallow the water to similarly drip fromtheir lower edges across alittle space and to wet another series K whichmay be similar boards shown as arran ed atri ht angles to the boards J.In a su ciently high tower there may be any number of successive series,down the surfaces of which the water flows, being very nearly ice-coldon the uppermost series and successively warmer and warmer on the lowerparts, the water having all the way absorbed the heat of the ascendingair, and usefully lowered it to a uniform temperature only a littleabove 32 Fah.

Above the first story a is a horizontal partition M liberally perforatedwith two series of apertures, one series m large and arranged to alloweasy and uniform upward passage of the great volume of air, the otherwhich may be much smaller, carrying tubes M" which extend downwardnearly the whole depth of the space (1. These tubes aflord protectedpassages through which the water descends by gravity without beinginfluenced by the violent motion of the air. The water which repeats thetraverse indefinitely is in this warmest portion of each circuit stillat a fairly low temperature, and the exterior of the tubes M is colderthan the air. The tower being practically a nonconductor of heat, thesetubes M anda layer of water below are the first cooling surfaces whichthe warm entering air meets.

Tobe reused continuously the water at each descent is distributed intothe refrigerating-pit at a temperature which is only moderately cold aswill be described farther on. Accumulating in contact with the coils Band sinking slowly downward between them, it rapidly parts with itsremaining heat, giving it up to the ammoniain the coils. The water ispreferably allowed to water tends to remove such coating by melt- J 1ng1t. When the apparatus is in operation accumulate as shown to a littleabove the tops of the coils B, but if the water'surface sinks lower,even if portions of the coils are above the water level and subjected tothe descending wash or rain from above, they will serve-well. Ifportionsbecome coated sooner than others, the pipes thus coated become less ableto receive heat rapidly from the exterior, and the other pipesorportions of pipes less thickly coated accumulate the me more rapidly,thus tending to equalize the conditions on the several pipes, but it isnot essential to my invention that theice coating should be uniform. Ipropose that some or all the ipes of eachtier shall freeze to- 80gether, orming. a series of parallel walls of ice C, leaving spacesbetween the tiers free from obstruction in which the water can freelysink.

. The evaporation of the ammonia within each coil tends to increase thethickn'ess of the ice on the exterior by extracting the caloric fromsuch water until the freezing point of water is reached. The descendingand variations occur, the thickness of the coating of ice will vary.When the temperature is for any brief period too low the ice coatingwill thicken and will extend farther up and will finally form into thickblocks or plates. When the temperature. is not low enough the attacksmade on the ice by the bath of nearly ice-cold water reduce thethickness. Between these contending influences the water descendingbetween the coils always reaches the bottom of ipeh ice-pit at verynearly or exactly 32'' D are perforated pipes takin the water 5 from allparts of the bottom 0 the refrigcrating-pit, and leading it outward andup ward in a single pipe D under the action of a steam pump D all asordinarily except that the perforated pipes'abstract the water from allparts of the bottom and that the pump and pipes outside are thicklyclothed to maintain the low temperature ofthe water. It is forced up bythe pum through a pipe D and is delivered into 1; e top of the tower ina constant stream at very nearly the same low temperature as obtains inthe bottom of the refrigerating-pit.

O is a horizontal pan forming the bottom of the first story. Short tubes0 extending 12o upward from well distributed points in this pan are ofsufficient number and size to permit the discharge and \further descentof all the water, but it can only thus descendby maintaining its surfaceat or above the level of the tops of these tubes. The descending waterthus detained a few inches deep on the pan 0 presents a cooling surfaceat its top to the torrent of air entering from all sides above it. 1 30Instead of losing any of the water pumped up, there is an excess, due tothe contribution thereto which is made by the ascending air as itstemperature is lowered during its ascent. Cold air holds less water thanwarm. The air soon attainsv a saturated condition. After such state isreached the air rising past the still colder water surfaces above notonly continues to be lowered in temperature, but also to deposit water.Such deposit adds to the quantity previously-in the circuit. Thisaddition varies. It is thus important to provide for a greatly variableoverflow.

I arran e to take away the surplus as the water is distributed downwardin the tower, and provide means for effecting this so as to take it awayin its warmest condition, as it descends through the warmest part of itscourse and accumulates in the pan 0. This peculiarity is important byreducing the cooling function required of the ammonia.

"P is a horizontal gate carried on a lever P which turns on a fixed pinP and is turnedvby a rod Q which extends down through an easy-fittinghole in the pan 0, and connects to a float Q. The latter rises and sinkswith the water level in the refrigerating-pit. When the water in therefrigeratingpit sinks, the sinking of the float Q raises the gate P andrestrains the discharge of warm water, thus raising the water level inthe pan 0, causin more to descend through the short pipes O and thus toraise the level again in the refrigerating-pit. It will be 0 erved thedischarge from the usefully regulated not by the heig t of the water msuch pan, but by the height of the water in the refrigerating-pit below.

T is a separate waste plpe controlled by the attendant by means of acock T. This is only to be used in emergencies. Ordinarily the cock T isclosed, andthe float Q which may simply be a piece of board lying flatin the cold water with room to rise an sink above the coils B, shiftsthe gate P so as to always discharge just enough.

The pipes B in which the intense cold is induced are arranged in tiers.After the apparatus has been working a short time dense ice C forms onthem as shown, and

thenceforward such ice serves as a means of insuring that the water isalways received by the pump at 32 Fah. When the water tends to bedelivered too warm, some of the ice 0 melts, this result being mainlynear the top of each tier, giving the taper form .to the iceapproximately as shown in the figure. When the cold is temporarily inexcess, the ice becomes thicker and also the height of the masses of iceC is increased. The attendant regulates the supply of ammonia, or it maybe regulated by any suitable automatic device, to keep that importantelement right, and the ice C preits warmest condition, avoidin anOisoutand forced up by the pump. The arrangement insures that the water in the're-' frigerating-pit, ice-cold at the bottom and but little warmer inthe successive layers above, is kept at a practically uniform levelunder allconditions, and that all the surplus due to additions of waterwhich has been extracted from the air is led away in which would beexperienced if it were allowed to sink into the refrigerating-pit.

U is a, fan blower driven preferably by the same engine which impels thepump D so as to be quickened and slowed in unison therewith. It performsthe double function of inducing a partial vacuum in the upper portion ofthe tower, and thus drawing in the air radially from all sides at thebottom and passing it up in opposition to the descending movement of thewater in the tower, and also of inducing a strong centrifugal, forcewhich throws all suspended watery particles out against the inclosingcasing. The bottom of the fan casing A is equipped with severalsuccessively increased cross dams A preferably three as shown, whicharrest any entrained water which may be moving along the inner surfacesin obedience tothe strong friction imposed by the rapidly moving air,and allows such water to descend through .the pipes A and be led away.The pipes are immersed at their delivery ends. to prevent the stronglyfanned air from escaping.

At the earlier stage of the descent of the water, but later stage of theascent and cooling of the air, the great volume of air is caused to moveoutward in divergent directions at the top of the tower and into anannular passage a in the enlargement A. In so moving it flows throughdifferent sized apertures in a crescent shaped wall A On the oppositeside from the final delivery passage the wall is entirely omitted,-thedischarge is free. Coinciding with the final delivery is the smallestaperture a At the intermediate position .on each side is an aperture aof intermediate size. The result is to secure a practical uniformity inthe drawing out of the air on all sides of the tower at the top. Theannular passage and unequally apertured wall, by inducing uniformity 1nthe radial escape of the air, tends to make the cooling provisionsequally eflicient at the top at all sides of the tower.

The effect is analogous to that of the unithe loss casing A from whenceafter its entrained water is arrested and taken outit is led by thecasing A to W, the ordinary pump blower.

This powerful machine receives the uni-v formly cold air, and compressesit to the tension required to enter the usual air-heating stove and bepassed into the furnace. W is the connection of this blower W to thestove and X the passage from the stove X to the blast furnace Y, whichrespectively perform their usual functions.

Modifications may be made without departing from the principle orsacrificing the advantages of the invention. Parts may be omitted oradded.

The blowing may be compounded, the last portion of the tension beingiven by an additional blower indicatef by the rectangle W I I may'circul'ate cold brine or other cooling medium through the cooling coilsB instead of evaporating ammonia therein.

I propose sometimes to work with the I may leave out the exhaust fan anddepend upon the aspiration of the blowing engine for drawing the airinto the tower and upward through the descending cold water.

I may do away with the exhaust fan drive, but still let all the air passthrough the fan and utilize the centrifugal force for separating anyentrained water from the air which it may contain.

Some of the features set forth herein are claimed in a separateapplication filed by me, October 26, 1908, Serial Number 459,495. Iclaim as my invention:

1. The combination with the blowing.

mechanism of a blast furnace of air-treating apparatus comprisingrefrigerating pipes, an inclosing pit, provisions for taking watertherefrom 1n a cold state and presenting it with a motion in onedirection to a current of air in the opposite direction so as to attaincounter-current heat exchanging, and provisions for returning such waterand repeating.

2. Air-treating apparatus comprising refrigerating pipes an inclosingpit, provisions for taking water therefrom in a cold state andpresenting such water with a downward motion to an upward current of airso as to attain a large measure of heat exchanging, provisions forreturning such water to the pit to be again cooled therein and deliveredin a uniformly cold condition to be again circulated, and provisionsfortaking away the surplus in the returning water before it reaches therefrigerating-pit.

3. Air-treating apparatus comprising refrigerating pipes-arranged invertical series, an inclosing pit, provisions for taking water therefromin a cold state and "presenting thereto an upward current of air,provisions for returnin such water tov the pit to be cooled therein anddelivered fi-om a low point in a uniformly cold condition, andprovisions for taking away surplus water by a gate P and float Q, thelatter means ar-.

ranged for automatically attaining the re moval of a just sufficientamount of the liquid without allowing it to warm the re frigerating-pit.

4. Air-treating apparatus comprising refrigerating pipes arranged invertical series, an inclosing refrigerating-pit, provisions for taking aliquid therefrom in a cold state and presenting thereto an ascendingcurrent of air, provisions for returning such liquid to the pit to becooled therein and delivered from a low point in a uniformly coldcondition, and provisions for taking away surplus liquid by a pipe T andcock T regulated byhand, and also by a gate P and fioat Q,

the latter means arranged for automatically attaining the removal of ajust sufiicient amount of the liquid without allowing it to warm therefrigerating-pit.

5. Air-treating apparatus comprising refrigerating pipes, an inclosing.pit, provisions for taking water uniformly cold from all parts of thebottom of such refri cratingpit, provisions for spreading suc water,

and uniformly delaying its descent by its friction, provisions forpresenting an ascending current of air thereto, and delivering such airradially into an annular space at the top and leading it thence to ablower.

6. Air-treating apparatus comprising refrigerating pipes, an inclosingrefrigeratingpit or tank, provisions for taking water therefrom in auniformly cold state and presenting an ascending current of air thereto,provisions for showering the water in a tower in such presentation,provisions by the cross-pieces J and K and the vessels E and pan 0 fordelaying the descent, and provisions for removing the surplus waterbeforeallowing it to affect the refrigeratingpit.

7. A cooling tower,,'provisions for distributing cold water to descendtherein, and provisions for collecting such water after each descent inav pit below, the latter having cooling coils arranged in tiers so that.ice the tower against .the descending motion of 10 of varying thicknessmay form on each side the water. of each coil, means for taking away thesur- Signed at New York this 15th day of plus water in the warmestcondition without September 1909.

allowing it to be brou ht in contact with a the contents of therefrigerating-pit, means LOUIS BLOCK for carrying the coldest water fromthe bot- Witnessesz. tom of said pit to the top of the tower, and HERMANMEYER,

"means for passing the air upward through GRACE VoLK.

